A buffer bar generally is used to control the speed of door opening/closing and a moving mechanism. The most common application is a door check for automatically and slowly closing the door without generating a big noise or damaging the door or door frame. It also may be adopted on other movable mechanisms that have a returning force and also need a resistant force against the movement to serve as a damping buffer. In general, the buffer resistant force generated by the buffer bar has two types of sources: a pneumatic type and an oil pressure type, or the so-called air pressure bar and oil pressure bar.
The conventional buffer bar has a big drawback, i.e. oil leakage or air leakage. This problem could cause dysfunction of the buffer bar. When used on cabinet windows or doors, in addition to the aforesaid problem, the factors of outside appealing and ornamental effect also have to be considered. The huge noise of the pneumatic bar and oil leakage of the oil pressure bar are problems not acceptable for general cabinets. While the huge noise of the pneumatic bar makes the cabinet not appealing, oil leakage of the oil pressure bar tends to smear the cabinet and articles held in the cabinet.
Hence the cabinet generally is not equipped with the buffer bar. As a result, a big noise is generated when the cabinet door is closed, and the cabinet door or cabinet is easily damaged. Because of the appealing consideration, someone introduced a buffer bar in a conventional hinge. However, while the hinge thus made has a buffer function, it is still not effective. And the problems mentioned above still exist.